About GCP Static IPs

GCP offers Static External IP and Static Internal IP as the equivalent of AWS Elastic IP. External IP is a global IP, and Internal IP is a private IP.

You can assign a name to a reserved internal IP and treat it as a single resource. A static internal IP assigned to one VM can be reassigned to another VM.

However, note that static internal IP addresses can only be assigned to VMs. For example, you cannot assign a reserved static internal IP to CloudSQL.